OMAHA, Neb. (KCAU) – More water continued to runoff into the Missouri River during the month of September, bringing more than 16 times the average runoff from Gavins Point Dam to Sioux City.
The runoff was record-setting, more than doubling the previous record for runoff between the two points, according to the U.S. Corps of Engineers (Corps).
Runoff at other dams upstream also saw runoff being higher than average. With the higher runoff in the upper basin of the Missouri River above Sioux City, the entire system also saw twice the record runoff.
The record runoff is due to the more than twice precipitation in eastern Montana, much of North Dakota, portions of South Dakota and northern Nebraska.
The Corps said that the forecast for 2019 for the entire upper basin is 61.0 million acre-feet (MAF), which would equal the highest runoff in recorded history and tying 2011.
Gavins Point Dam is forecast to maintain releases of 80,000 cubic feet per second through October. The reservoir level was at 1206.2 feet at the end of September. By the end of October, it is forecast to go up to 1207.5 feet as dams upstream release their excess water.
The Missouri River mainstem reservoir system is occupied by 64 MAF. Of the system, the 16.3 MAF flood control zone holds 7.9 MAF.
John Remus, the chief of the Corps’ Missouri River Basin Water Management Division, said that with the high reservoirs and runoff, the high releases won’t just be at Gavins Point. Releases all along the system will be above average through November as the Corps tries to release all the stored floodwaters.
“We are monitoring the situation very closely and will make any necessary adjustments. Failure to evacuate the stored flood water will lead to increased risk of flooding in 2020,” Remus said .
The system’s powerplants generated 1393 million kWh of electricity, while the average is 895 million kWh. They are projected to generate 13.3 billion kWh of electricity for the year.